Optical stimulation system with on-demand monitoring and methods of making and using

ABSTRACT

An optical stimulation system includes a light source configured to produce light for optical stimulation; a light monitor; an optical lead coupled, or coupleable, to the light source and the light monitor; and a control module coupled, or coupleable, to the light source and the light monitor. The control module includes a memory, and a processor coupled to the memory and configured for receiving a request for verification or measurement of a light output value; in response to the request, receiving, from the light monitor, a measurement of light generated by the light source; and, based on the measurement, reporting a response to the request.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/040,254, filed Sep. 22, 2020, which is the U.S. national stageapplication of PCT Application No. PCT/US19/22938, filed Mar. 19, 2019,which claims the benefit under 35 U.S.C. § 119(e) of U.S. ProvisionalPatent Application Ser. No. 62/647,555, filed Mar. 23, 2018, all ofwhich are incorporated herein by reference.

FIELD

The present disclosure is directed to the area of implantable opticalstimulation systems and methods of making and using the systems. Thepresent disclosure is also directed to implantable optical stimulationleads having mechanism for on-demand monitoring of light output, as wellas methods of making and using the optical stimulation systems.

BACKGROUND

Implantable optical stimulation systems can provide therapeutic benefitsin a variety of diseases and disorders. For example, optical stimulationcan be applied to the brain either externally or using an implantedstimulation lead to provide, for example, deep brain stimulation, totreat a variety of diseases or disorders. Optical stimulation may alsobe combined with electrical stimulation.

Stimulators have been developed to provide therapy for a variety oftreatments. A stimulator can include a control module (for generatinglight or electrical signals sent to light sources in a lead), one ormore leads, and one or more light sources coupled to, or disposedwithin, each lead. The lead is positioned near the nerves, muscles,brain tissue, or other tissue to be stimulated.

BRIEF SUMMARY

In one aspect, an optical stimulation system includes a light sourceconfigured to produce light for optical stimulation; a light monitor; anoptical lead coupled, or coupleable, to the light source and the lightmonitor; and a control module coupled, or coupleable, to the lightsource and the light monitor. The control module includes a memory, anda processor coupled to the memory and configured for receiving a requestfor verification or measurement of a light output value; in response tothe request, receiving, from the light monitor, a measurement of lightgenerated by the light source; and, based on the measurement, reportinga response to the request. In at least some aspects, the light source ispart of the optical lead.

In at least some aspects, the processor is further configured fordirecting the light monitor to make the measurement. In at least someaspects, the processor is further configured for comparing themeasurement to an expected light output value, wherein reporting theresponse includes reporting the response based on the comparison of themeasurement to the expected light output value. In at least someaspects, the processor is further configured for directing the lightsource to generate light that is expected to be at the expected lightoutput level at a site where light is collected for measurement by thelight monitor.

In at least some aspects, the light monitor is configured to measure alight output level directly from the light source. In at least someaspects, the optical lead further includes a first optical waveguideconfigured to receive light generated by the light source and emit thelight from a distal portion of the optical lead for the opticalstimulation and a second optical waveguide configured to receive aportion of the light emitted from the distal portion of the optical leadand direct the received portion of the light to the light monitor,wherein the light monitor is configured to measure a light output levelfrom the light emitted from the distal portion of the optical lead.

In at least some aspects, reporting the response includes sending areport to a device from which the request was sent. In at least someaspects, reporting the response includes reporting positively if themeasurement is within a threshold amount of an expected light outputlevel. In at least some aspects, reporting the response includes sendinga warning if the measurement deviates by more than a threshold amountfrom an expected light output level. In at least some aspects, reportingthe response includes prompting or directing a user to adjust theoptical stimulation if the measurement deviates by more than a thresholdamount from an expected light output level. In at least some aspects,reporting the response includes automatically adjusting the opticalstimulation if the measurement deviates by more than a threshold amountfrom an expected light output level. In at least some aspects, receivingthe request includes receiving a stimulation program or set ofstimulation parameters which initiates the request.

In at least some aspects, the optical stimulation system furtherincludes an external device configured for communication with thecontrol module, wherein the external device includes an input device anda processor coupled to the input device and configured for receiving auser input that includes the request for verification or measurement ofthe light output value; and communicating the request to the controlmodule. In at least some aspects, the external device is a programmingunit, a clinician programmer, or a patient remote control. In at leastsome aspects, reporting the response includes communicating the responseto the request to the external device, wherein the external devicefurther includes a display and the processor of the external device isfurther configured for reporting the response to the request on thedisplay. In at least some aspects, reporting the response to the requeston the display includes prompting or directing, on the display, a userto adjust the optical stimulation if the measurement deviates by morethan a threshold amount from an expected light output level. In at leastsome aspects, reporting the response to the request on the displayincludes displaying a warning if the measurement deviates by more than athreshold amount from an expected light output level. In at least someaspects, reporting the response to the request on the display includesdisplaying a positive message if the measurement is within a thresholdamount of an expected light output level.

In another aspect, a non-transitory processor readable storage mediaincludes instructions for monitoring optical stimulation using anoptical stimulation system including a light source, a light monitor,and an optical lead coupled to the light source, wherein execution ofthe instructions by one or more processor devices performs actions,including: receiving a request for verification or measurement of alight output value; in response to the request, receiving, from thelight monitor, a measurement of light generated by the light source;and, based on the measurement, reporting a response to the request.

In yet another aspect, a method of monitoring optical stimulation usingan optical stimulation system including a light source, a light monitor,and an optical lead coupled to the light source, includes receiving arequest for verification or measurement of a light output value; inresponse to the request, receiving, from the light monitor, ameasurement of light generated by the light source; and, based on themeasurement, reporting a response to the request.

In at least some aspects of the non-transitory processor readablestorage media or the method, the actions or steps further includedirecting the light monitor to make the measurement. In at least someaspects of the non-transitory processor readable storage media or themethod, the actions or steps further include comparing the measurementto an expected light output value, wherein reporting the responseincludes reporting the response based on the comparison of themeasurement to the expected light output value. In at least some aspectsof the non-transitory processor readable storage media or the method,the actions or steps further include directing the light source togenerate light that is expected to be at the expected light output levelat a site where light is collected for measurement by the light monitor.

In at least some aspects of the non-transitory processor readablestorage media or the method, reporting the response includes sending areport to a device from which the request was sent. In at least someaspects of the non-transitory processor readable storage media or themethod, reporting the response includes reporting positively if themeasurement is within a threshold amount of an expected light outputlevel. In at least some aspects of the non-transitory processor readablestorage media or the method, reporting the response includes sending awarning if the measurement deviates by more than a threshold amount froman expected light output level.

In at least some aspects of the non-transitory processor readablestorage media or the method, reporting the response includes promptingor directing a user to adjust the optical stimulation if the measurementdeviates by more than a threshold amount from an expected light outputlevel. In at least some aspects of the non-transitory processor readablestorage media or the method, reporting the response includesautomatically adjusting the optical stimulation if the measurementdeviates by more than a threshold amount from an expected light outputlevel. In at least some aspects of the non-transitory processor readablestorage media or the method, receiving the request includes receiving astimulation program or set of stimulation parameters which initiates therequest.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention aredescribed with reference to the following drawings. In the drawings,like reference numerals refer to like parts throughout the variousfigures unless otherwise specified.

For a better understanding of the present invention, reference will bemade to the following Detailed Description, which is to be read inassociation with the accompanying drawings, wherein:

FIG. 1 is a schematic overview of one embodiment of components of anoptical or optical/electrical stimulation system, including anelectronic subassembly;

FIG. 2 is a schematic side view of one embodiment of an arrangementincluding a light source, an optional light monitor, an optical lead,and a connector lead;

FIG. 3 is a schematic cross-sectional view of one embodiment of theoptical lead of FIG. 2 ;

FIG. 4A is a schematic side view of one embodiment of a control moduleconfigured to electrically couple to a lead or lead extension;

FIG. 4B is a schematic side view of one embodiment of a lead extensionconfigured to electrically couple a lead to the control module of FIG.4A;

FIG. 5 is a schematic side view of one embodiment of an electricalstimulation system that includes an electrical stimulation leadelectrically coupled to a control module;

FIG. 6 is a schematic side view of one embodiment of anoptical/electrical stimulation system with an optical/electricalstimulation lead coupled to a control module having a light source;

FIG. 7 is a schematic overview of one embodiment of components of aprogramming unit for an optical or optical/electrical stimulationsystem;

FIG. 8 is a flowchart for one embodiment of a method of monitoringoptical stimulation;

FIG. 9 is a flowchart for one embodiment of a method of prompting ordirecting a user to adjust stimulation parameters;

FIG. 10 is a flowchart for one embodiment of a method of automaticallyadjusting stimulation parameters; and

FIG. 11 is a diagram of one embodiment of a user interface formonitoring light output for optical stimulation.

DETAILED DESCRIPTION

The present disclosure is directed to the area of implantable opticalstimulation systems and methods of making and using the systems. Thepresent disclosure is also directed to implantable optical stimulationleads having mechanism for on-demand monitoring of light output, as wellas methods of making and using the optical stimulation systems.

In some embodiments, the implantable optical stimulation system onlyprovides optical stimulation. In other embodiments, the stimulationsystem can include both optical and electrical stimulation. In at leastsome of these embodiments, the optical stimulation system can be amodification of an electrical stimulation system to also, or instead,provide optical stimulation. Optical stimulation may include, but is notnecessarily limited to, stimulation resulting from response toparticular wavelengths or wavelength ranges of light or from thermaleffects generated using light or any combination thereof.

FIG. 1 is a schematic overview of one embodiment of components of anoptical stimulation system 100 (or combination optical/electricalstimulation system) including an electronic subassembly 110 disposedwithin a control module (for example, an implantable or external pulsegenerator or implantable or external light generator). It will beunderstood that the optical stimulation system can include more, fewer,or different components and can have a variety of differentconfigurations including those configurations disclosed in thestimulator references cited herein. In at least some embodiments, theoptical stimulation system may also be capable of providing electricalstimulation through optional electrodes 126.

In at least some embodiments, selected components (for example, a powersource 112, an antenna 118, a receiver 102, a processor 104, and amemory 105) of the optical stimulation system can be positioned on oneor more circuit boards or similar carriers within a sealed housing of acontrol module. Any suitable processor 104 can be used and can be assimple as an electronic device that, for example, produces signals todirect or generate optical stimulation at a regular interval or theprocessor can be capable of receiving and interpreting instructions froman external programming unit 108 that, for example, allows modificationof stimulation parameters or characteristics.

The processor 104 is generally included to control the timing and othercharacteristics of the optical stimulation system. For example, theprocessor 104 can, if desired, control one or more of the timing, pulsefrequency, amplitude, and duration of the optical stimulation. Inaddition, the processor 104 can select one or more of the optionalelectrodes 126 to provide electrical stimulation, if desired. In someembodiments, the processor 104 selects which of the optionalelectrode(s) are cathodes and which electrode(s) are anodes.

Any suitable memory 105 can be used. The memory 105 illustrates a typeof computer-readable media, namely computer-readable storage media.Computer-readable storage media may include, but is not limited to,nonvolatile, non-transitory, removable, and non-removable mediaimplemented in any method or technology for storage of information, suchas computer readable instructions, data structures, program modules, orother data. Examples of computer-readable storage media include RAM,ROM, EEPROM, flash memory, or other memory technology, magnetic storagedevices, or any other medium which can be used to store the desiredinformation and which can be accessed by a processor.

The processor 104 is coupled to a light source 120. Any suitable lightsource can be used including, but not limited to, light emitting diodes(LEDs), organic light emitting diodes (OLEDs), laser diodes, lamps,light bulbs, or the like or any combination thereof. In at least someembodiments, the optical stimulation system may include multiple lightsources. In at least some embodiments, each of the multiple lightsources may emit light having a different wavelength or differentwavelength range. Any suitable wavelength or wavelength range can beused including, but not limited to, visible, near infrared, andultraviolet wavelengths or wavelength ranges. In at least someembodiments, the optical stimulation system includes a light source thatemits in the orange, red, or infrared wavelength ranges (for example, inthe range of 600 to 1200 nm or in the range of 600 to 700 nm or in therange of 610 to 650 nm or 620 nm or the like.) In at least someembodiments, the optical stimulation system includes a light source thatemits in the green or blue wavelength ranges (for example, in the rangeof 450 to 550 nm or in the range of 495 to 545 nm or the like.) Awavelength or wavelength range of a light source may be selected toobtain a specific therapeutic, chemical, or biological effect.

As described below, the light source 120 may be disposed within thecontrol module or disposed external to the control module such as, forexample, in a separate unit or module or as part of an optical lead. Theprocessor 104 provides electrical signals to operate the light source120 including, for example, directing or driving the generation of lightby the light source, pulsing the light source, or the like. For example,the processor 104 can direct current from the power source 112 tooperate the light source 120. In at least some embodiments, the lightsource 120 is coupled to one or more optical waveguides (such as anoptical fiber or other optical transmission media) disposed in anoptical lead 122. In at least some embodiments, the optical lead 122 isarranged so that one or more of the optical waveguides emits light fromthe distal portion of the optical lead (for example, the distal end orat one or more positions along the distal portion of the lead or anycombination thereof).

Optionally, the processor 104 is also coupled to a light monitor 124that is used to monitor or measure light from the light source 122. Forexample, the light monitor 124 can produce electrical or other signalsin response to the light received by the light monitor. Any suitablelight monitor 124 can be used including, but not limited to,photodiodes, phototransistors, photomultipliers, charge coupled devices(CCDs), light dependent resistors (LRDs), photo-emissive cells,photo-conductive ells, photo-voltaic cells, photo-junction devices, orthe like or any combination thereof. The light monitor 124 may be usedto measure or monitor the light emitted by the light source 120 or fromthe optical waveguide(s) (or other optical transmission media) of theoptical lead 122. In at least some embodiments, the light monitor 124may be coupled to one or more optical waveguides (or other opticaltransmission media) of the optical lead 122 to transmit the light alongan optical lead for measurement or monitoring.

Any power source 112 can be used including, for example, a battery suchas a primary battery or a rechargeable battery. Examples of other powersources include super capacitors, nuclear or atomic batteries, fuelcells, mechanical resonators, infrared collectors, flexural poweredenergy sources, thermally-powered energy sources, bioenergy powersources, bioelectric cells, osmotic pressure pumps, and the like. Asanother alternative, power can be supplied by an external power sourcethrough inductive coupling via an antenna 118 or a secondary antenna.The external power source can be in a device that is mounted on the skinof the user or in a unit that is provided near the user on a permanentor periodic basis. In at least some embodiments, if the power source 112is a rechargeable battery, the battery may be recharged using theantenna 118 and a recharging unit 116. In some embodiments, power can beprovided to the battery for recharging by inductively coupling thebattery to the external recharging unit 116.

In at least some embodiments, the processor 104 is coupled to a receiver102 which, in turn, is coupled to an antenna 118. This allows theprocessor 104 to receive instructions from an external source, such asprogramming unit 108, to, for example, direct the stimulation parametersand characteristics. The signals sent to the processor 104 via theantenna 118 and the receiver 102 can be used to modify or otherwisedirect the operation of the optical stimulation system. For example, thesignals may be used to modify the stimulation characteristics of theoptical stimulation system such as modifying one or more of stimulationduration and stimulation amplitude. The signals may also direct theoptical stimulation system 100 to cease operation, to start operation,to start charging the battery, or to stop charging the battery. In otherembodiments, the stimulation system does not include the antenna 118 orreceiver 102 and the processor 104 operates as initially programmed.

In at least some embodiments, the antenna 118 is capable of receivingsignals (e.g., RF signals) from an external programming unit 108 (suchas a clinician programmer or patient remote control or any other device)which can be programmed by a user, a clinician, or other individual. Theprogramming unit 108 can be any unit that can provide information orinstructions to the optical stimulation system 100. In at least someembodiments, the programming unit 108 can provide signals or informationto the processor 104 via a wireless or wired connection. One example ofa suitable programming unit is a clinician programmer or other computeroperated by a clinician or other user to select, set, or programoperational parameters for the stimulation. Another example of theprogramming unit 108 is a remote control such as, for example, a devicethat is worn on the skin of the user or can be carried by the user andcan have a form similar to a pager, cellular phone, or remote control,if desired. In at least some embodiments, a remote control used by apatient may have fewer options or capabilities for altering stimulationparameters than a clinician programmer.

Optionally, the optical stimulation system 100 may include a transmitter(not shown) coupled to the processor 104 and the antenna 118 fortransmitting signals back to the programming unit 108 or another unitcapable of receiving the signals. For example, the optical stimulationsystem 100 may transmit signals indicating whether the opticalstimulation system 100 is operating properly or not or indicating whenthe battery needs to be charged or the level of charge remaining in thebattery. The processor 104 may also be capable of transmittinginformation about the stimulation characteristics so that a user orclinician can determine or verify the characteristics.

FIG. 2 illustrates one embodiment of an arrangement 200 for an opticalstimulation system that can be used with a control module (see, FIG. 4). In at least some embodiments, the control module may be originallydesigned for use with an electrical stimulation system and adapted foruse as an optical stimulation system via the arrangement 200.

The arrangement 200 includes a base unit 228 a light source 120 disposedin a housing 230, an optical lead 122 with one or more emission regions232 a, 232 b of a distal portion from which light is emitted, and aconnector lead 234 with one or more terminals 236 for coupling to acontrol module or lead extension, as described below. The optical lead122 and connector lead 234, independently, may be permanently, orremovably, coupled to the base unit 228. If removably coupleable to thebase unit 228, the optical lead 122, connector lead 234, or both willhave corresponding arrangements (for example, terminals and contacts)for transmission of light (for the optical lead) or electrical signals(for the connector lead) to the base unit 228. The one or more emissionregions 232 a, 232 b may include a tip emission region 232 a that emitsdistally away from the lead or may include a side emission regions 232 bthat emit at the sides of the lead or any combination thereof.

In addition to the light source 120, the base unit 228 can optionallyinclude a light monitor 124. The base unit 228 may also includecomponents such as electrical components associated with the lightsource 120 or light monitor 124, a heat sink, optical components (forexample, a lens, polarizer, filter, or the like), a light shield toreduce or prevent light emission out of the housing of the base unit orto reduce or prevent extraneous light from penetrating to the lightmonitor 124 or the like. The housing 230 of the base unit 228 can bemade of any suitable material including, but not limited to, plastic,metal, ceramic, or the like, or any combination thereof. If the baseunit 228 is to be implanted, the housing 230 is preferably made of abiocompatible material such as, for example, silicone, polyurethane,titanium or titanium alloy, or any combination thereof.

In at least some embodiments, the optical lead 122, as illustrated incross-section in FIG. 3 , includes a lead body 241 and one or moreoptical waveguides 238 (or other optical transmission media) fortransmission of light from the light source 120 with emission along theone or more emission regions 232 a, 232 b disposed on the distal portionof the optical lead. In the illustrated embodiment, the light is emittedat the distal tip of the lead. In other embodiments, the light may beemitted at one or more points along the length of at least the distalportion of the lead. In some embodiments with multiple light sources,there may be separate optical waveguides for each light source or lightfrom multiple light sources may be transmitted along the same opticalwaveguide(s). The optical lead 122 may also include one or more opticalcomponents, such as a lens, diffuser, polarizer, filter, or the like, atthe distal portion of the lead (for example, at the terminal end of theoptical waveguide 238) to modify the light transmitted through theoptical waveguide.

In at least some embodiments that include a light monitor 124, theoptical lead 122 may include one or more optical waveguides 240 (orother optical transmission media) that receive light emitted from thelight source 120 and transmitted by the optical waveguide 238 in orderto measure or monitor the light emitted at the one or more emissionregions 232 a, 232 b of the optical lead. The optical waveguide(s) 240transmit light from the one or more emission regions 232 a, 232 b of theoptical lead to the light monitor 124 in the base unit 228. The opticallead 122 may also include one or more optical components, such as alens, diffuser, polarizer, filter, or the like, at the distal portion ofthe lead (for example, at the terminal end of the optical waveguide 240)to modify the light received by the optical waveguide(s) 240.

The connector lead 234 includes conductors (e.g., wires—not shown)disposed in a lead body extending along the connector lead 234 to theterminals 236 on the proximal end of the connector lead. As analternative, the connector lead 234 may be permanently attached to acontrol module or other device where the conductors then attach tocontact points within the control module or other device. The conductorscarry electrical signals to the base unit 228 and the light source 120and, optionally, other electrical components in the base unit foroperation of the light source 120. The conductors may also carryelectrical signals from the optional light monitor 124 in the base unit228 to the control module or other device. These electrical signals maybe generated by the light monitor 124 in response to light received bythe light monitor.

FIG. 4A is a schematic side view of one embodiment of proximal ends 442of one or more leads (for example, connector lead 234 of FIG. 2 ) orlead extensions 460 (see, FIG. 4B) coupling to a control module 446 (orother device) through one or more control module connectors 444. The oneor more proximal ends 442 include terminals 448 (for example, terminals236 of connector lead 234).

The control module connector 444 defines at least one port 450 a, 450 binto which a proximal end 442 can be inserted, as shown by directionalarrows 452 a and 452 b. The control module 446 (or other device) candefine any suitable number of ports including, for example, one, two,three, four, five, six, seven, eight, or more ports.

The control module connector 444 also includes a plurality of connectorcontacts, such as connector contact 454, disposed within each port 450 aand 450 b. When the proximal end 442 is inserted into the ports 450 aand 450 b, the connector contacts 454 can be aligned with a plurality ofterminals 448 disposed along the proximal end(s) 442. Examples ofconnectors in control modules are found in, for example, U.S. Pat. Nos.7,244,150 and 8,224,450, which are incorporated by reference.

The control module 446 typically includes a connector housing 445 and asealed electronics housing 447. An electronic subassembly 110 (see, FIG.1 ) and an optional power source 112 (see, FIG. 1 ) are disposed in theelectronics housing 447.

FIG. 4B is a schematic side view of a portion of another embodiment ofan optical stimulation system 100. The optical stimulation system 100includes a lead extension 460 that is configured to couple one or moreproximal ends 442 of a lead to the control module 446. In FIG. 4B, thelead extension 460 is shown coupled to a single port 450 defined in thecontrol module connector 444. Additionally, the lead extension 460 isshown configured to couple to a single proximal end 442 of a lead (forexample, the connector lead 234 of FIG. 2 ).

A lead extension connector 462 is disposed on the lead extension 460. InFIG. 4B, the lead extension connector 462 is shown disposed at a distalend 464 of the lead extension 460. The lead extension connector 462includes a connector housing 466. The connector housing 466 defines atleast one port 468 into which terminals 448 of the proximal end 442 ofthe lead can be inserted, as shown by directional arrow 470. Theconnector housing 466 also includes a plurality of connector contacts,such as connector contact 472. When the proximal end 442 is insertedinto the port 468, the connector contacts 472 disposed in the connectorhousing 466 can be aligned with the terminals 448 for electricalcoupling.

In at least some embodiments, the proximal end 474 of the lead extension460 is similarly configured as a proximal end 442 of a lead. The leadextension 460 may include a plurality of electrically conductive wires(not shown) that electrically couple the connector contacts 472 to aproximal end 474 of the lead extension 460 that is opposite to thedistal end 464. In at least some embodiments, the conductive wiresdisposed in the lead extension 460 can be electrically coupled to aplurality of terminals (not shown) disposed along the proximal end 474of the lead extension 460. In at least some embodiments, the proximalend 474 of the lead extension 460 is configured for insertion into aconnector disposed in another lead extension (or another intermediatedevice). In other embodiments (and as shown in FIG. 4B), the proximalend 474 of the lead extension 460 is configured for insertion into thecontrol module connector 144.

In some embodiments, the optical stimulation system may also be anelectrical stimulation system. FIG. 5 illustrates schematically oneembodiment of an electrical stimulation system 500. The electricalstimulation system includes a control module 446 (e.g., a stimulator orpulse generator) and an electrical stimulation lead 580 coupleable tothe control module 446. The same control module 446 can be utilized withthe arrangement 200 (FIG. 2 ) for optical stimulation and an electricalstimulation lead 580. With respect to the optical/electrical stimulationsystem of FIG. 1 , the control module 446 can include the electronicsubassembly 110 (FIG. 1 ) and power source 112 (FIG. 1 ) and theelectrical stimulation lead 580 can include the electrodes 126. Theoptical arrangement 200 of FIG. 2 can be inserted into another port ofthe control module 446.

The lead 580 includes one or more lead bodies 582, an array ofelectrodes 583, such as electrode 126, and an array of terminals (e.g.,448 in FIG. 4A-4B) disposed along the one or more lead bodies 582. In atleast some embodiments, the lead is isodiametric along a longitudinallength of the lead body 582. Electrically conductive wires, cables, orthe like (not shown) extend from the terminals to the electrodes 126.Typically, one or more electrodes 126 are electrically coupled to eachterminal. In at least some embodiments, each terminal is only connectedto one electrode 126.

The lead 580 can be coupled to the control module 446 in any suitablemanner. In at least some embodiments, the lead 580 couples directly tothe control module 446. In at least some other embodiments, the lead 580couples to the control module 446 via one or more intermediate devices.For example, in at least some embodiments one or more lead extensions460 (see e.g., FIG. 4B) can be disposed between the lead 580 and thecontrol module 446 to extend the distance between the lead 580 and thecontrol module 446. Other intermediate devices may be used in additionto, or in lieu of, one or more lead extensions including, for example, asplitter, an adaptor, or the like or combinations thereof. It will beunderstood that, in the case where the electrical stimulation system 500includes multiple elongated devices disposed between the lead 580 andthe control module 446, the intermediate devices may be configured intoany suitable arrangement.

The electrical stimulation system or components of the electricalstimulation system, including one or more of the lead bodies 582 and thecontrol module 446, are typically implanted into the body of a patient.The electrical stimulation system can be used for a variety ofapplications including, but not limited to, brain stimulation, neuralstimulation, spinal cord stimulation, muscle stimulation, and the like.

The electrodes 126 can be formed using any conductive, biocompatiblematerial. Examples of suitable materials include metals, alloys,conductive polymers, conductive carbon, and the like, as well ascombinations thereof. In at least some embodiments, one or more of theelectrodes 126 are formed from one or more of: platinum, platinumiridium, palladium, palladium rhodium, or titanium. The number ofelectrodes 126 in each array 583 may vary. For example, there can betwo, four, six, eight, ten, twelve, fourteen, sixteen, or moreelectrodes 126. As will be recognized, other numbers of electrodes 126may also be used.

Examples of electrical stimulation systems with leads are found in, forexample, U.S. Pat. Nos. 6,181,969; 6,295,944; 6,391,985; 6,516,227;6,609,029; 6,609,032; 6,741,892; 7,244,150; 7,450,997; 7,672,734;7,761,165; 7,783,359; 7,792,590; 7,809,446; 7,949,395; 7,974,706;8,831,742; 8,688,235; 6,175,710; 6,224,450; 6,271,094; 6,295,944;6,364,278; and 6,391,985; U.S. Patent Applications Publication Nos.2007/0150036; 2009/0187222; 2009/0276021; 2010/0076535; 2010/0268298;2011/0004267; 2011/0078900; 2011/0130817; 2011/0130818; 2011/0238129;2011/0313500; 2012/0016378; 2012/0046710; 2012/0071949; 2012/0165911;2012/0197375; 2012/0203316; 2012/0203320; 2012/0203321; 2012/0316615;2013/0105071; 2011/0005069; 2010/0268298; 2011/0130817; 2011/0130818;2011/0078900; 2011/0238129; 2011/0313500; 2012/0016378; 2012/0046710;2012/0165911; 2012/0197375; 2012/0203316; 2012/0203320; and2012/0203321, all of which are incorporated by reference in theirentireties.

FIG. 6 illustrates other optional embodiments. For example, FIG. 6illustrates one embodiment of an optical/electrical stimulation system100 with a lead 690 with both electrodes 126 and an optical waveguidethat emits light from the from one more emission regions 232 a, 232 b ofthe lead. In some embodiments, the lead 690 can be coupled to the baseunit 228 and connector lead 234 of FIG. 2 with conductors (andoptionally connector contacts if the lead 690 or connector lead 234 areremovable from the base unit 228) electrically coupling the terminals236 of the connector lead to the electrodes 126 of the lead 690.

FIG. 6 also illustrates one embodiment of a control module 446 that alsoincludes a light source 120 within the control module. Such anarrangement can replace the base unit 228 and connector lead 234 of FIG.2 and may include a lead extension 460.

FIG. 7 illustrates one embodiment of a programming unit 108. Theprogramming unit 108 can include a computing device 700 or any othersimilar device that includes a processor 702 and a memory 704, a display706, and an input device 708.

The computing device 700 can be a computer, tablet, mobile device, orany other suitable device for processing information or programming anoptical stimulation system. The computing device 700 can be local to theuser or can include components that are non-local to the computerincluding one or both of the processor 702 or memory 704 (or portionsthereof). For example, in at least some embodiments, the user mayoperate a terminal that is connected to a non-local computing device. Inother embodiments, the memory can be non-local to the user.

The computing device 700 can utilize any suitable processor 702including at least one hardware processors that may be local to the useror non-local to the user or other components of the computing device.The processor 702 is configured to execute instructions provided to theprocessor 702, as described below.

Any suitable memory 704 can be used for the computing device 702. Thememory 704 illustrates a type of computer-readable media, namelycomputer-readable storage media. Computer-readable storage media mayinclude, but is not limited to, nonvolatile, non-transitory, removable,and non-removable media implemented in any method or technology forstorage of information, such as computer readable instructions, datastructures, program modules, or other data. Examples ofcomputer-readable storage media include RAM, ROM, EEPROM, flash memory,or other memory technology, CD-ROM, digital versatile disks (“DVD”) orother optical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, or any other medium which canbe used to store the desired information and which can be accessed by acomputing device.

Communication methods provide another type of computer readable media;namely communication media. Communication media typically embodiescomputer-readable instructions, data structures, program modules, orother data in a modulated data signal such as a carrier wave, datasignal, or other transport mechanism and include any informationdelivery media. The terms “modulated data signal,” and “carrier-wavesignal” includes a signal that has at least one of its characteristicsset or changed in such a manner as to encode information, instructions,data, and the like, in the signal. By way of example, communicationmedia includes wired media such as twisted pair, coaxial cable, fiberoptics, wave guides, and other wired media and wireless media such asacoustic, RF, infrared, and other wireless media.

The display 706 can be any suitable display device, such as a monitor,screen, display, or the like, and can include a printer. In at leastsome embodiments, the display 706 may form a single unit with thecomputing device 700. The input device 708 can be, for example, akeyboard, mouse, touch screen, track ball, joystick, voice recognitionsystem, or any combination thereof, or the like.

The methods and systems described herein may be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Accordingly, the methods and systemsdescribed herein may take the form of an entirely hardware embodiment,an entirely software embodiment or an embodiment combining software andhardware aspects. Systems referenced herein typically include memory andtypically include methods for communication with other devices includingmobile devices. Methods of communication can include both wired andwireless (for example, RF, optical, or infrared) communications methodsand such methods provide another type of computer readable media; namelycommunication media. Wired communication can include communication overa twisted pair, coaxial cable, fiber optics, wave guides, or the like,or any combination thereof. Wireless communication can include RF,infrared, acoustic, near field communication, Bluetooth™, or the like,or any combination thereof.

In at least some instances, optical stimulation is typically not felt bythe patient, but the effectiveness of the optical stimulation therapyoften results from the long-term application of the therapy. Failure toproduce the programmed optical stimulation therapy may reduce oreliminate the efficacy of the therapy. In at least some instances, theoptical stimulation system may register that the control module isdirecting the light source to produce the optical stimulation therapy,but a failure, damage, or other defect within the optical components(for example, the light source or optical lead) or other components mayresult in reduction in, or complete loss of, effectiveness of theoptical stimulation therapy. The patient or clinician may be unaware ofthe failure or the reduction or loss of effectiveness of the therapy.

In many instances, it is desirable to have a mechanism for the opticalstimulation system to confirm that the system is delivering the opticalstimulation and, preferably, at the selected light output value(measured, for example, at the distal end of the optical lead or at thelight source). Accordingly, it is useful for the system to have thecapability to verify, at user request, that the optical stimulationsystem is still providing the optical stimulation at the selected outputlevel. In at least some embodiments, the optical stimulation system canrelay the verification to the patient or the clinician (or both) orindicate that an anomaly is detected.

A user, such as a patient, clinician, other care giver, or othersuitable individual may operate a programming unit 108 (for example, aclinician programmer or a patient remote control or other device, suchas a mobile phone, tablet, or computer) that is in communication withthe processor 104 to request a verification or a measurement of thelight output level. Such a request might be made during a programmingsession for the optical stimulation system or during a clinical visit orat any other time to verify that the optical stimulation is producingthe desired stimulation. In some embodiments, any of the devices listedabove can have a user interface with a control that the user actuates tomake the request.

In at least some embodiments, the request may be made as part of anotheroperation and, optionally, without an actuation of a specific requestcontrol. For example, in a programming session or other activity, whenone or more of the stimulation parameters (for example, the expectedlight output level or another parameter related to that level) ischanged or when a new stimulation program is executed or activated, suchan activity may include, within the processor instructions, a requestfor verification or a measurement of the light output level.

In response to the request, the processor 104 directs the light monitor124 to measure the light output value at the distal end of the opticallead 122 (or alternatively emitted by the light source 120). In at leastsome embodiments, the optical stimulation system may store measurementof light output values to provide historical measurement data. Forexample, such measurements may be stored in a memory 105 of a controlmodule 446 or memory 704 of a programming unit 108. In at least someembodiments, the stored measurements may be used for troubleshooting oranalysis of the system's light output.

The processor 104 evaluates the resulting measurement to determinewhether the optical stimulation system is producing the programmed lighttherapy. As an example, the processor 104 may compare the measurementand an expected light output value and determine whether the measurementdeviates from the expected light output value by more than a thresholdamount. In at least some embodiments, the threshold amount may beprogrammed or otherwise selected by a user, such as a clinician orprogrammer. The threshold amount may be a numerical value or apercentage or any other suitable parameter that represents an acceptabledistance from the expected light output value. In at least someembodiments, the expected light output value may be programmed orotherwise selected by a user, such as a clinician or programmer. In atleast some embodiments, if the measurement deviates from the expectedlight output value by more than a threshold amount, one or moreadditional measurements may be made to confirm the deviation.

The system may also include one or more controls for requestingmeasurement of the light output value (once or more than once to obtainan average of light output values) in order to establish a baselineduring programming or other operation of the optical stimulation system.In at least some embodiments, this baseline may be used for the expectedlight output level.

FIG. 11 illustrates one embodiment of a user interface 1100 formonitoring light output. The illustrated embodiment includes a control1102 for requesting a measurement, a display window 1104 for receiving amessage or warning or other information related to the measurement, anda control 1106 for requesting a baseline measurement. It will beunderstood that many other interface designs are possible and that thecontrols for monitoring light output can be integrated into aprogramming unit or other user interface.

In at least some embodiments, the processor may convert measurements ofthe light monitor in mA or mV (or other suitable units) to light outputvalues in mW (or other suitable units.) A calibration table orcalibration formula may be used for this conversion. Examples ofgenerating and using calibration tables and formulas are found in U.S.Provisional Patent Application Ser. No. 62/647,561, entitled “OpticalStimulation Systems with Calibration and Methods of Making and Using”(Attorney Docket No. BSNC-1-688.0), filed on even date herewith,incorporated herein by reference in its entirety. Alternatively, anyother mechanism for conversion can be used.

In at least some embodiments, the threshold amount or any of the othersettings described herein or any combination of these settings may bepassword protected (or safeguarded using any other method ofauthentication such as, for example, two factor authentication,biometrics, or the like or any combination thereof) to prevent or hinderchanging these settings by individuals other than an authorized personsuch as a clinician. In at least some embodiments, the opticalstimulation system may include a user interface (for example, as part ofa programming unit 108) to set, adjust, change, or modify one or more ofthese settings.

In response to request and the subsequent measurement, in at least someembodiments, the processor may activate an audible, visual, or vibratorymessage when the measured light output level is within the threshold ofthe expected light output value. For example, a green light orconfirmatory message may be displayed on the programming unit, remotecontrol, or other device used to make the request.

In at least some embodiments, if a deviation from the expected lightoutput value is detected or confirmed, an audible, visual, vibratory, orother warning is presented. For example, the warning may be sent to thedevice used to make the request. For example, a red light or warningmessage may be displayed on, or an audible warning message or sound maybe emitted by, the programming unit, remote control, or other deviceused to make the request. For example, the programming unit, remotecontrol, or other device used to make the request may include a buzzeror speaker for providing an audible warning.

In at least some embodiments, when the request is made by the patientoutside of a programming session, the warning may direct the patient tocontact or visit the clinician. In at least some embodiments, when therequest is made by the patient outside of a programming session, if adeviation is detected or confirmed, an audible, visual, vibratory, orother warning is sent to the clinician. For example, the control modulemay communicate to a remote control or recharging unit with the patientthat may send the warning to the clinician over the Internet, over amobile network, or through other wired or wireless communication.

In at least some embodiments, the optical stimulation system can providean indication (for example, through a patient's remote control) to thepatient or clinician to recommend adjustment to the therapy. Forexample, the optical stimulation system may direct the patient orclinician to adjust one or more stimulation parameters (for example, theamount of light generated by the light source or the signal sent to thelight source) and may propose amount for the adjustment.

In at least some embodiments, if the patient or clinician is directed toadjust the therapy, the system may obtain further measurements of thelight output value using the light monitor 124 to observe the results ofthe adjustments. The system may iteratively direct the patient orclinician to adjust the therapy and then obtain measurements to observethe results. In at least some embodiments, if adjustments to the therapyare ineffective or result in unacceptable light output levels (forexample, levels that are too high or too low), the system may take oneor more corrective actions such as, for example, operating the systemusing a set of stimulation parameters that are selected to produce asafe level of stimulation, halt the stimulation, or send a warning tothe patient or clinician or both, or any combination thereof.

In at least some embodiments, the measurements from the light monitor124 are provided to the processor 104 of a control module 446 or theprocessor 702 of a programming unit 108 or a processor of anotherdevice. The processor includes an algorithm or other computer programthat utilizes the measurements by the light monitor 124 and compares themeasurement to expected light output values or other metrics todetermine whether the desired optical stimulation is being delivered. Insome instances, if the measurements indicate that the desired opticalstimulation is not being delivered, the system may generate a warning,take a corrective action, or any combination thereof.

FIG. 8 is a flowchart of one embodiment of a method of monitoringoptical stimulation. In step 802, a request is received from a user (forexample, a patient or clinician) to verify or measure the light outputlevel. For example, the user may activate a control on a programmingunit (such as a clinician programmer or a patient remote control), amobile device (such as a mobile phone or a tablet), or computer to makethe request. As another example, the request may be part of theinstructions executed by a processor when one or more stimulationparameters are input, modified, or delivered to a control module or whena stimulation program is activated or selected. In step 804, theprocessor directs the light monitor 124 (or any other suitable device)to measure the light output level is measured by the light monitor 124.In at least some embodiments, multiple measurements may be made andaveraged together or otherwise combined. In step 806, the measured lightoutput level is compared to an expected light output level. In at leastsome embodiments, if the measured light output level deviates from theexpected light output level by more than a threshold amount, one or moreadditional measurements may be taken to confirm the deviation. In step808 the system reports the result of the measurement and comparison. Ifthe measured light output level is within a threshold amount of theexpected light output level, then a positive report (or no report) ispresented. If the measured light output level deviates by more than athreshold amount from the expected light output level, then a warningmay be produced, as described above, or the device may take a correctiveaction, as described above, or any combination thereof.

In some embodiments, the optical stimulation system may suggest acorrective action when the measured light output level deviates by morethan a threshold amount from the expected light output level. Examplesof corrective actions can be one or more of prompting or directing thepatient or clinician to adjust one or more of the stimulation parametersto select a different stimulation program, automatically adjusting oneor more of the stimulation parameters, operating the system using a setof stimulation parameters or stimulation program that is selected toproduce a safe level of stimulation, halt the stimulation, or the likeor any combination thereof.

As indicated a corrective action may include prompting or directingadjustment to one or more stimulation parameters or automaticallyadjusting one or more stimulation parameters. FIG. 9 is a flowchart ofone embodiment of a method of prompting or directing adjustment to oneor more stimulation parameters. In step 902, the measurement by thelight monitor 124 is analyzed. For example, the measurement may beanalyzed to determine if the light output value is higher or lower inintensity than expected.

In step 904, the processor determines an adjustment to one or more ofthe stimulation parameters in view of the analysis. Examples ofstimulation parameters that can be adjusted include, but are not limitedto, the amount of light generated by the light source, the expectedlight output level, the driving signal sent to the light source, lightpulse or optical stimulation duration, light pulse patterns, other pulsetiming parameters, and the like. The analysis and generation of theadjustment can be performed by the processor 104, external programmingunit 108, control module 446, or any combination thereof. As analternative to a specific adjustment to one or more stimulationparameters, the processor may select a predefined stimulation program.

In step 906, the adjustment to the one or more stimulation parameters(or the selected predefined stimulation program) is presented to a userfor entry. For example, the adjustment may be presented to a patient ona remote control, programming unit, mobile phone, tablet, or computerthat is in communication with the control module. As another example,the adjustment may be presented to a clinician or other care giver on aprogramming unit, mobile phone, tablet, computer that is incommunication with the control module. The device may direct or promptthe user to make the adjustment (or select the predefined stimulationprogram). If the user does not respond, the device optionally may send awarning to the patient, a clinician, a care giver, or any other suitableindividual or device. In some embodiments, the system may automaticallymake the adjustment (or select the predefined stimulation program) ifthe user does not respond in a specified time period. In otherembodiments, the system does not make the adjustment (or select thepredefined stimulation program) automatically.

FIG. 10 is a flowchart of one embodiment of a method of automaticallyadjusting one or more stimulation parameters. In step 1002, themeasurement by the light monitor 124 is analyzed. For example, themeasurement may be analyzed to determine if the light output value ishigher or lower in intensity than expected.

In step 1004, the processor determines an adjustment to one or more ofthe stimulation parameters in view of the analysis. Examples ofstimulation parameters that can be adjusted include, but are not limitedto, the amount of light generated by the light source, the expectedlight output level, the driving signal sent to the light source, lightpulse or optical stimulation duration, light pulse patterns, other pulsetiming parameters, and the like. The analysis and generation of theadjustment can be performed by the processor 104, external programmingunit 108, control module 446, or any combination thereof. As analternative to a specific adjustment to one or more stimulationparameters, the processor may select a predefined stimulation program.

In step 1006, the system automatically makes the adjustment to the oneor more stimulation parameters (or selects the predefined stimulationprogram). In at least some embodiments, the system sends a notice of theadjustment to the patient on a remote control, programming unit, mobilephone, tablet, or computer that is in communication with the controlmodule or to a clinician or other care giver on a programming unit,mobile phone, tablet, computer that is in communication with the controlmodule.

In at least some embodiments of the methods illustrated in FIGS. 9 and10 , the system may utilize a step-wise methodology to altering, orprompting or directing alteration of, the stimulation parameters. Forexample, the system may alter, or prompt or direct alteration of, one ormore stimulation parameters based on the light monitor measurements andthen observe the results of the alteration as measured using the lightmonitor (or based on other input such as patient or clinician feedback.)In at least some embodiments, the system waits for a latency period toallow the light output value to be measurable by the light monitor or toallow a clinical effect (therapeutic or side effect) to be noticeable tothe patient, clinician, or other individual.

It will be understood that each block of the flowchart illustrations,and combinations of blocks in the flowchart illustrations and methodsdisclosed herein, can be implemented by computer program instructions.These program instructions may be provided to a processor to produce amachine, such that the instructions, which execute on the processor,create means for implementing the actions specified in the flowchartblock or blocks disclosed herein. The computer program instructions maybe executed by a processor to cause a series of operational steps to beperformed by the processor to produce a computer implemented process.The computer program instructions may also cause at least some of theoperational steps to be performed in parallel. Moreover, some of thesteps may also be performed across more than one processor, such asmight arise in a multi-processor computer system. In addition, at leastone process may also be performed concurrently with other processes, oreven in a different sequence than illustrated without departing from thescope or spirit of the invention.

The computer program instructions can be stored on any suitablecomputer-readable medium including, but not limited to, RAM, ROM,EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (“DVD”) or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store the desired informationand which can be accessed by a computing device.

A system can include one or more processors that can perform the methods(in whole or in part) described above. The methods, systems, and unitsdescribed herein may be embodied in many different forms and should notbe construed as limited to the embodiments set forth herein.Accordingly, the methods, systems, and units described herein may takethe form of an entirely hardware embodiment, an entirely softwareembodiment or an embodiment combining software and hardware aspects. Themethods described herein can be performed using any type of processor orany combination of processors where each processor performs at leastpart of the process. In at least some embodiments, the processor mayinclude more than one processor.

The above specification provides a description of the manufacture anduse of the invention. Since many embodiments of the invention can bemade without departing from the spirit and scope of the invention, theinvention also resides in the claims hereinafter appended.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. An optical stimulation system, comprising: alight source configured to produce light for optical stimulation; alight monitor; an optical lead coupled, or coupleable, to the lightsource and the light monitor; and a control module coupled, orcoupleable, to the light source and the light monitor, wherein the lightsource, light monitor, optical lead, and control module are implantable,the control module comprising a memory, and a processor coupled to thememory and configured for performing a verification or measurement of alight output value; in response to the performing, receiving, from thelight monitor, a measurement of light generated by the light source,wherein the light monitor is configured to measure a light output leveldirectly from the light source; and when the measurement deviates froman expected light output value by more than a threshold amount,performing at least one of the following: sending a warning; or taking acorrective action.
 2. The optical stimulation system of claim 1, furthercomprising an external device configured for communication with thecontrol module, wherein the processor is configured to send the warningto the external device and the external device is configured for, inresponse to receiving the warning, providing a visual or auditorymessage to a user.
 3. The optical stimulation system of claim 2, whereinthe external device is a programming unit, a clinician programmer, or apatient remote control.
 4. The optical stimulation system of claim 2,wherein the corrective action comprises prompting or directing a user,through the external device, to adjust optical stimulation when themeasurement deviates by more than a threshold amount from an expectedlight output level.
 5. The optical stimulation system of claim 1,wherein sending a warning comprises causing the control module to emit avibratory or auditory warning.
 6. The optical stimulation system ofclaim 1, wherein the corrective action comprises prompting or directinga user to adjust optical stimulation when the measurement deviates bymore than a threshold amount from an expected light output level.
 7. Theoptical stimulation system of claim 6, wherein the corrective actionfurther comprises, after the user adjusts the optical stimulation,receiving, from the light monitor, a second measurement of lightgenerated by the light source; and, when the second measurement deviatesfrom an expected light output value by more than a threshold amount,prompting or directing the user to adjust the optical stimulation. 8.The optical stimulation system of claim 1, wherein the corrective actioncomprises automatically adjusting optical stimulation when themeasurement deviates by more than a threshold amount from an expectedlight output level.
 9. The optical stimulation system of claim 8,wherein the corrective action further comprises, after automaticallyadjusting the optical stimulation, receiving, from the light monitor, asecond measurement of light generated by the light source; and, when thesecond measurement deviates from an expected light output value by morethan a threshold amount, automatically adjusting the optical stimulationagain.
 10. The optical stimulation system of claim 1, wherein thecorrective action comprises halting optical stimulation.
 11. The opticalstimulation system of claim 1, wherein the processor is furtherconfigured for, when the measurement deviates from the expected lightoutput value by more than the threshold amount, receiving, from thelight monitor, a second measurement of light generated by the lightsource to confirm the deviation when the second measurement alsodeviates from the expected light output value by more than the thresholdamount.
 12. An optical stimulation system, comprising: a light sourceconfigured to produce light for optical stimulation; a light monitor; anoptical lead coupled, or coupleable, to the light source and the lightmonitor, wherein the optical lead comprises a first optical waveguideconfigured to receive light generated by the light source and emit thelight from a distal portion of the optical lead for the opticalstimulation and a second optical waveguide configured to receive aportion of the light emitted from the distal portion of the optical leadand direct the received portion of the light to the light monitor; and acontrol module coupled, or coupleable, to the light source and the lightmonitor, wherein the light source, light monitor, optical lead, andcontrol module are implantable, the control module comprising a memory,and a processor coupled to the memory and configured for performing averification or measurement of a light output value; in response to theperforming, receiving, from the light monitor, a measurement of lightgenerated by the light source, wherein the light monitor is configuredto measure a light output level from the light emitted from the distalportion of the optical lead; and when the measurement deviates from anexpected light output value by more than a threshold amount, performingat least one of the following: sending a warning; or taking a correctiveaction.
 13. The optical stimulation system of claim 12, furthercomprising an external device configured for communication with thecontrol module, wherein the processor is configured to send the warningto the external device and the external device is configured for, inresponse to receiving the warning, providing a visual or auditorymessage to a user.
 14. The optical stimulation system of claim 13,wherein the corrective action comprises prompting or directing a user,through the external device, to adjust optical stimulation when themeasurement deviates by more than a threshold amount from an expectedlight output level.
 15. The optical stimulation system of claim 12,wherein sending a warning comprises causing the control module to emit avibratory or auditory warning.
 16. The optical stimulation system ofclaim 12, wherein the corrective action comprises prompting or directinga user to adjust optical stimulation when the measurement deviates bymore than a threshold amount from an expected light output level. 17.The optical stimulation system of claim 16, wherein the correctiveaction further comprises, after the user adjusts the opticalstimulation, receiving, from the light monitor, a second measurement oflight generated by the light source; and, when the second measurementdeviates from an expected light output value by more than a thresholdamount, prompting or directing the user to adjust the opticalstimulation.
 18. The optical stimulation system of claim 12, wherein thecorrective action comprises automatically adjusting optical stimulationwhen the measurement deviates by more than a threshold amount from anexpected light output level.
 19. The optical stimulation system of claim12, wherein the corrective action comprises halting optical stimulation.20. The optical stimulation system of claim 12, wherein the processor isfurther configured for, when the measurement deviates from the expectedlight output value by more than the threshold amount, receiving, fromthe light monitor, a second measurement of light generated by the lightsource to confirm the deviation when the second measurement alsodeviates from the expected light output value by more than the thresholdamount.